Biogeochemistry of trace metals in the subarctic and Arctic oceans under a rapidly changing climate

快速变化的气候下亚北极和北冰洋微量金属的生物地球化学

• 批准号: RGPIN-2019-05561
• 负责人: Cullen, Jay
• 金额: $ 2.19万
• 依托单位: University of Victoria
• 依托单位国家: 加拿大
• 项目类别: Discovery Grants Program - Individual
• 财政年份: 2019
• 资助国家: 加拿大
• 起止时间: 2019-01-01 至 2020-12-31
• 项目状态: 已结题
• 来源: https://www.nserc-crsng.gc.ca/ase-oro/Details-Detailles_eng.asp?id=683365
• 关键词: Biogeochemistry; trace; metals; subarctic; Arctic

Microscopic marine plants and bacteria form the base of the ocean food web. The amount and chemical form of metals present in seawater can prevent plants and bacteria from growing either because they are scarce and essential nutrients like iron or zinc, or they are toxic when too much is available like lead or mercury. Metals can change how productive the marine food web can be by controlling which species, and how much of the microscopic plants and bacteria, can grow. Ultimately, metals then can control the oceans ability to take up greenhouse gases and slow climate change. Similarly, the health and sustainability of our fisheries can depend on the biological availability (bioavailability) of metal nutrients and toxins. Given that Canada is a country surrounded by three oceans this research has clear economic and cultural relevance to our citizens. *** My research group develops and uses highly sensitive analytical tools and approaches like mass spectrometry and electrochemistry to study metal chemistry in the ocean. The long-term goals of my research program are to understand the processes that control the distribution, chemical form and resulting bioavailability of trace metals, and how altered physical and chemical conditions in response to climate change are likely to impact these metal properties in the ocean. Recently, my research group has made significant progress towards these goals through the development and application of powerful analytical methods in both the field and the laboratory. We have focused on metals that control primary production and microbe community structure (e.g. Fe, Cu and Zn), serve as paleoceanographic tracers that provide important information regarding the oceans role is past climate change (e.g. Cd, Ag), or potentially toxic heavy metals that might negatively impact the marine ecosystem (Cu, Ag and Cd). Over the next 5 years my short term research objectives are to: 1) examine how changing temperature, ocean acidification and light where sea ice melts in high latitude ocean surface waters will impact biologically important metals; 2) unravel how much metals are either added or removed from the ocean near the continents; and 3) determine how decreasing oxygen levels in the ocean impact the relative distribution of metals.*** Our data will allow for better incorporation of metal chemistry in coupled atmosphere-ocean models designed to predict the response of marine systems in the Canadian subarctic and Arctic to regional warming, ocean acidification, ocean deoxygenation and changing sea ice and light regimes. In addition, a more thorough understanding of what controls the basin scale distribution of trace metals and their relationships with other ocean plant nutrients will aide in efforts to verify existing and develop new tools that can help us understand the oceans role in past climate change.**

微观海洋植物和细菌构成了海洋食品网的基础。海水中存在的金属的数量和化学形式可以防止植物和细菌生长，因为它们是稀缺和铁或锌的必需营养素，或者当铅或汞（如铅或汞）可用时，它们是有毒的。金属可以通过控制哪些物种以及微观植物和细菌的生长可以改变海洋食品网的生产力。最终，金属可以控制海洋占用温室气体并缓慢气候变化的能力。同样，我们的渔业的健康和可持续性可以取决于金属养分和毒素的生物学可用性（生物利用度）。鉴于加拿大是一个被三个海洋包围的国家，这项研究与我们的公民具有明显的经济和文化相关性。 ***我的研究小组开发并使用高度敏感的分析工具和方法，例如质谱和电化学来研究海洋中的金属化学。我的研究计划的长期目标是了解控制痕量金属的分布，化学形式和产生的生物利用度的过程，以及对气候变化的物理和化学条件的变化如何影响海洋中的这些金属特性。最近，我的研究小组通过在该领域和实验室中开发和应用强大的分析方法来朝着这些目标取得了重大进展。 我们专注于控制初级生产和微生物群落结构（例如Fe，Cu和Zn）的金属，作为古复活示踪剂，提供有关海洋角色的重要信息是过去的气候变化（例如CD，AG）或可能对海洋生态系统产生负面影响的潜在有毒重金属（CU，AG，AG和CD）。在接下来的5年中，我的短期研究目标是：1）检查温度，海洋酸化和光线如何在高纬度海面水中融化的海冰会影响生物学上重要的金属； 2）解散从大洲附近的海洋中添加或去除多少金属； 3）确定海洋中的氧气水平降低如何影响金属的相对分布。此外，对控制盆地量金属的盆地量表分布及其与其他海洋植物营养的关系的更透彻了解将有助于核实现有工具并开发新工具，以帮助我们了解海洋在过去的气候变化中的作用。** **